Profile adjustment method, apparatus, and program

ABSTRACT

An object of the present invention is to make it possible to perform a quantitative evaluation not influenced by experience and sensitivity of a user, upon adjustment of a profile.  
     The adjustment of first conversion data for converting device independent data included in a profile describing characteristics of a device into device dependent data is achieved by inputting sample data which is the device independent data, converting the sample data into the device dependent data using the first conversion data, converting the converted device dependent data into the device independent data using second conversion data which is conversion data included in the profile and which is conversion data for converting the device dependent data into the device independent data, and calculating a color difference between the sample data and the device independent data.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to techniques for adjusting aprofile describing characteristics of a device.

[0003] 2. Related Background Art

[0004] In a conventional color adjustment, a color adjustment isperformed to a specific image and the thus adjusted image is thenprinted out. However, if the color adjustment is performed to thespecific image, each time the image to be objective is changed, it isnecessary that the color adjustment is redone every time.

[0005] On the other hand, if color matching is performed using a deviceprofile (hereinafter, referred to as a profile) describingcharacteristics to each input/output device, it becomes possible toperform a color management consistency from input to output. In thismethod, even if the image to be objective is changed, there is nonecessity that the color adjustment is redone. In FIG. 14, aconceptional view of general color matching is shown.

[0006] Input data of a color space dependent on a source device such asRGB or CMYK is converted into XYZ data or Lab data of a color space(PCS: Profile Connection Space) independent of a device by an inputprofile. Since a color out of a color reproduction range of an outputdevice can not be represented by the output device, in order that allthe colors are contained in the color reproduction range of the outputdevice, a color space compression is performed to the input dataconverted into data of the color space independent of the device. And,after the color space compression is performed, the input data isconverted from the color space independent of the device into the colorspace dependent on the output device such as RGB or CMYK.

[0007] However, even in color matching using such a profile, if accuracyof the used profile is not sufficient, ideal color matching results cannot be obtained. Besides, even if the profile accuracy immediately aftermaking is sufficient, device characteristics change by aging or thelike, and if the profile is not adjusted, there is also a case thatsatisfactory color matching results can not be obtained.

[0008] Therefore, in case that sufficient profile accuracy can not beobtained, and in case that the profile goes not to match the devicecharacteristics, the color adjustment of the profile becomes necessary.

[0009] A conventional color adjustment method of a profile is performedby a user performing the color adjustment with monitor-displaying theimage to be objective, and the results are reflected on the profile.

[0010] However, since image quality evaluation of the color adjustmentwas by eye observation evaluation of the user, quality of the adjustedprofile was influenced by experience and sensitivity of the user.

[0011] Besides, in the color adjustment by the eye observationevaluation on a monitor, it was hard to detect a different color (orcolor gamut) from an original image on a preview image, and if notexperienced, it was difficult to master.

SUMMARY OF THE INVENTION

[0012] The present invention has been made in view of the above points,and its objects are as follows.

[0013] An object is to make it possible to perform a quantitativeevaluation not influenced by experience and sensitivity of a user, uponadjustment of a profile.

[0014] Another object is to make it possible to check a history ofadjustment by making it possible to register adjustment to the history.

[0015] One invention described in this application is directed to aprofile adjustment method for adjusting first conversion data forconverting device independent data included in a profile describingcharacteristics of a device into device dependent data, comprising thesteps of

[0016] inputting sample data which is the device independent data,

[0017] converting the sample data into the device dependent data usingthe first conversion data,

[0018] converting the converted device dependent data into the deviceindependent data using second conversion data which is conversion dataincluded in the profile and which is conversion data for converting thedevice dependent data into the device independent data, and

[0019] calculating a color difference between the sample data and thedevice independent data.

[0020] Another invention described of this application is directed to aprofile adjustment method comprising:

[0021] an adjustment step of adjusting first conversion data forconverting device independent data included in a profile describingcharacteristics of a device into device dependent data,

[0022] an evaluation step of evaluating results of the adjustment, and

[0023] a registration step of registering the adjustment in a history,

[0024] wherein the history is displayed, and an evaluation correspondingto the adjustment registered in the history is displayed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a system construction diagram in case that a CMYKprinter is utilized in place of a calibration machine;

[0026]FIG. 2 is a color matching construction necessary for profilecolor adjustment;

[0027]FIG. 3 is a monitor display screen;

[0028]FIG. 4 is a processing flow for detecting an area in which colordifference is large;

[0029]FIG. 5 is a monitor display screen when the area in which colordifference is large is detected;

[0030]FIGS. 6A, 6B, 6C and 6D are conceptional views showing an examplein which a color adjustment profile is utilized;

[0031]FIGS. 7A, 7B and 7C are conceptional views showing spot coloradjustment;

[0032]FIG. 8 is a user interface screen of color selection;

[0033]FIG. 9 is a monitor display screen upon color selection;

[0034]FIG. 10 is a user interface screen of color adjustment;

[0035]FIG. 11 is a monitor display screen showing a color adjustmenthistory and color-difference log;

[0036]FIG. 12 is a display screen of color-difference statistic;

[0037]FIG. 13 is a processing flow showing the whole color adjustment;and

[0038]FIG. 14 is a conceptional view showing general color matching.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] (Embodiment 1)

[0040] Although color adjustment of a profile may be performed to anyprofile of an input profile of a digital camera or a scanner, a monitorprofile of a monitor, and an output profile of an RGB printer or a CMYKprinter, this embodiment will be described using the output profile ofthe CMYK printer as an example.

[0041] Besides, although as a sample image used for color adjustment,any image of an RGB image and a CMYK image may be utilized in accordancewith application, this embodiment will be described using the CMYK imageas an example.

[0042] Besides, a profile describes characteristics of a device anddescribes a relation between device dependent data and deviceindependent data (PCS data). This embodiment will be described using anICC profile according to a format determined by ICC (International ColorConsortium). The ICC profile includes A2B as data for converting devicedependent data into PCS data, B2A as data for converting PCS data intodevice dependent data, color reproduction range information on a device(gamut tag), etc.

[0043] Before color adjustment of a profile is described, an example ofa color matching system construction in case that a CMYK printer is usedin place of a calibration machine, is shown in FIG. 1.

[0044] In FIG. 1, reference numeral 101 denotes CMYK image data forcalibration machine showing an image for color calibration output,reference numeral 102 denotes a calibration machine, reference numeral103 denotes a color calibration output matter printed out from thecalibration machine 102, reference numeral 104 denotes an output profile(source profile) of the calibration machine 102 as a target, referencenumeral 105 denotes an output profile (destination profile) of a CMYKprinter, reference numeral 106 denotes the CMYK printer, and referencenumeral 107 denotes a printed-out matter from the CMYK printer 106.

[0045] Utilizing profile preparation software or the like, the outputprofile 105 of the CMYK printer 106 is prepared. Note that as the outputprofile 104 of the calibration machine 102, it is supposed that optimumone has been prepared in advance.

[0046] Next, to the CMYK image data 101 for calibration machine, colormatching is performed by setting the output profile 104 as a sourceprofile and the output profile 105 as a destination profile. Morespecifically, the CMYK image data 101 for calibration machine isconverted into PCS data using A2B data of the output profile 104 forcalibration machine, and converted into CMYK data for CMYK printer usingB2A data of the output profile for CMYK printer.

[0047] In general, in case of performing color calibration, a colorcalibration output image 101 is printed out from the calibration machine102. The cost of the calibration machine is high and a long time isrequired for printing out. Therefore, if the same color reproduction asa color calibration output utilizing the calibration machine, utilizingan inexpensive CMYK printer and color matching, can be realized, thecost can be reduced, and in addition, the printing time can also beshortened.

[0048] If a profile for CMYK is properly prepared, the printed-outmatter 107 in which substantially the same color reproduction as thecolor calibration output matter 103 output from the calibration machineis realized, is obtained. However, in case of not obtaining sufficientprofile accuracy, color adjustment of the profile becomes necessary.

[0049] In the color matching system of FIG. 1, it is desirable that thecolor taste of the printed-out matter 107 from the CMYK printer matchesthe color taste of the color calibration output matter from thecalibration machine 102. Therefore, in this embodiment, using thecalibration machine 102 as a target device, in order to adjust colorreproduction of the CMYK printer, B2A data of the output profile forCMYK printer is adjusted.

[0050] (Adjustment of Profile)

[0051] Hereinafter, as adjustment of a profile, an example in whichcolor adjustment is performed to the output profile 105 of the CMYKprinter 106, will be described.

[0052] In color adjustment, the optimum color adjustment is performed bycombining an eye observation evaluation by a sample image for coloradjustment and a quantitative evaluation by color difference.

[0053]FIG. 2 shows a system construction of color matching necessary forcolor adjustment of a profile, using a display image in this embodiment,and FIG. 3 shows a monitor display screen for color adjustment of theprofile in this embodiment.

[0054] In FIG. 2, reference numeral 201 denotes a sample image for coloradjustment, reference numeral 202 denotes a CMYK value of the sampleimage for color adjustment, and reference numeral 203 is a Lab value (oran xyz value) obtained by applying A2B data of the output profile 104 ofthe calibration machine 102 to the CMYK value 202. Reference numeral 204denotes a monitor profile of a monitor in which a user performs coloradjustment, and reference numeral 205 denotes an image displayed basedon monitor RGB in which color matching is performed by applying theoutput profile 104 of the calibration machine 102 and the monitorprofile 204 to the sample image.

[0055] Reference numeral 206 denotes a Lab value obtained by applyingB2A data of the output profile 105 of the CMYK printer 106 to the Labvalue 203, and further applying A2B data of the output profile of theCMYK printer 106 to it. And, reference numeral 207 denotes an imagedisplayed based on monitor RGB in which color matching is performed byapplying the monitor profile 204 to the Lab value 206.

[0056] The Lab value 203 is equivalent to the Lab value in case that theCMYK value 202 is printed out by the calibration machine 102 and thepatch is color-measured. Also, the Lab value 206 is equivalent to theLab value in which the patch in which color matching is performed to theCMYK value 202 using the output profile 104 of the calibration machine102 as the source profile, and the output profile 105 of the CMYKprinter 106 as the destination profile, and printed out by the CMYKprinter 106, is color-measured.

[0057] In short, the Lab value 203 is a color printed out by thecalibration machine 102, and the Lab value 206 shows a color printed outin order to reproduce the color as the same color on the CMYK printer106. And, each of the color matching images 205 and 207 is an image inwhich the printed-out color is simulated on the monitor.

[0058] In FIG. 3 showing the monitor display screen for color adjustmentof a profile, the left side shows the color matching image 205 (originalimage), and the right side shows the color matching image 207 (previewimage).

[0059] If the output profile 105 of the CMYK printer 106 is an idealprofile, the original image 205 and the preview image 207 must coincidewith each other on the monitor screen of FIG. 3 (though the color out ofthe color reproduction range of the CMYK printer 106 is excepted).

[0060] However, actually, since the accuracy of the profile prepared byprofile preparation software is not sufficient, and it is a limit ofaccuracy by CLUT, part that not coincide, appears between the originalimage 205 and the preview image 207.

[0061] (Detection of Adjusted Color Using Color Difference as Index)

[0062] Although it is good if the part in which color reproduction isdifferent can be found by eye observation on the monitor, by evaluationonly by eye observation, if not experienced, it is even difficult todetect a color to be adjusted.

[0063] Therefore, in this embodiment, in order to make it easy to detectthe color to be adjusted, an area in which color difference is large isblinked on the preview image 207.

[0064]FIG. 4 shows processing for blinking the area in which colordifference is large. Besides, FIG. 5 shows a monitor screen display whenthe area in which color difference is large, is blinked.

[0065] In a sample image input unit 401, the sample image data 202 forcolor adjustment is read in. Next, following processing of FIG. 2, theoriginal image 205 and the preview image 207 are generated. Upon this,in a Lab image 203 generation unit 402, processing for generating theLab image 203 from the sample image data 202, is performed. In a Labimage 206 generation unit 403, processing for generating the Lab image206 from the sample image data 202, is performed.

[0066] Note that, in processing of FIG. 4, in order to performgeneration processing of the original image 205 and the generationprocessing of the preview image 207 in parallel, the Lab image 203generation unit 402 and the Lab image 206 generation unit 403 areseparately provided.

[0067] Next, by a color-difference image generation unit 404, colordifference is obtained to each pixel of the Lab image 203 and the Labimage 206. When it is supposed that a Lab value of the Lab image 203 is(L₁, a₁, b₁) and the Lab value of the Lab image 206 at the same positionas the Lab value of the Lab image 203 is (L₂, a₂, b₂), using, forexample, an CIE94 color-difference equation, color difference can beobtained as follows. $\begin{matrix}{{\Delta \quad E} = \sqrt{\left( \frac{\Delta \quad L}{1.0} \right)^{2} + \left( \frac{\Delta \quad H}{1 + {0.015 \times C_{1}}} \right)^{2} + \left( \frac{\Delta \quad C}{1 + {0.045 \times C_{1}}} \right)^{2}}} & \left( {{Equation}\quad 1.1} \right)\end{matrix}$

[0068] where

ΔL=L₂L₁  (Equation 1.2),

ΔH=H₂H₁  (Equation 1.3),

[0069] and

ΔC=C₂C₁  (Equation 1.4).

[0070] But, since, in the color out of the color reproduction range,color difference can not be made zero even if an ideal profile has beenused, utilizing the color reproduction range information (gamut Tag) ofthe output profile 105 of the CMYK printer 106, in case that the Labvalue (L₁, a₁, b₁) is out of the color reproduction range, a flagindicating that it is out of the color reproduction range is set inplace of the value of color difference.

[0071] Besides, in this embodiment, although the Lab image 203 and theLab image 206 are temporarily held, the Lab image 203 and the Lab image206 may be obtained from the sample image 201 to each pixel, and colordifference may be directly calculated to generate a color differenceimage. Besides, the utilized color difference equation may also be byEuclid distance to the Lab values of two points.

[0072] In this embodiment, for simplifying processing, color differenceobtained to each pixel is normalized as follows by the maximum colordifference ΔE_(max) and the minimum color difference ΔE_(min) in thepixel.

ΔE _(normalized)=(ΔE−ΔE _(min))/(ΔE _(max) −ΔE _(min))  (Equation 1.5)

[0073] Next, by a user threshold-value input 405, a threshold value thata user want to detect is input (see 405 of FIG. 5). When a slider bar ismoved in a color difference increase direction, color difference as thethreshold value increases. When the slider bar is moved in a colordifference decrease direction, color difference as the threshold valuedecreases.

[0074] The threshold value designated by the user is set by a userthreshold-value setting unit 406, and it is compared with the value of acolor difference image generated by a color-difference image generationunit 404. And, by a mask setting unit 408, if the value of the colordifference image is larger than the threshold value, mask setting isperformed to the preview image 207, and if below the value of the colordifference image, mask setting is not performed. Here, in the colordifference image, as for a pixel for which a flag out of the colorreproduction range is set, processing of mask setting is skipped. Whencomparison is completed to all pixels, on the basis of information onset mask, mask blink is performed on the preview image 207 (410 of FIG.5). And, at need, the user resets the threshold value.

[0075] Note that, in this embodiment, although the value of the colordifference image is normalized, it may not be normalized and the usermay directly set the value of color difference. Besides, the feedbackmethod to the user is not limited to mask blink.

[0076] By performing mask blink to the preview image, since the user canrapidly and objectively detect an area in which color difference islarge, it becomes possible to color-adjust from a color in which colordifference is large.

[0077] (Color Adjustment Method of B2A Data)

[0078] Color adjustment of a profile by eye observation is performedwith comparing the original image 205 and the preview image 207 so thatthe preview image 207 may approach the original image 205 by coloradjustment. Also, in color adjustment of the profile by color differenceevaluation, color adjustment of the Lab value 206 is performed so thatcolor difference between the Lab value 203 and the Lab value 206 maydecrease. And, by results of color adjustment being reflected to B2Adata of the output profile 105, B2A data in which color adjustment isperformed can be generated.

[0079] As a method for reflecting the color adjustment results to theB2A data of the output profile 105, a method utilizing a coloradjustment profile as an example will be described.

[0080]FIG. 6A shows a state that no color adjustment profile (Lab→Lab)is inserted. This is equivalent to a case in which a color adjustmentprofile 601 of through (input and output have the same value) isinserted.

[0081]FIG. 6B shows a state that the color adjustment profile 601(Lab→Lab) is added. In this state, contents of the color adjustmentprofile 601 are changed to perform color adjustment. But, since, in thecolor adjustment profile, the only input value (Lab) of B2A of theoutput profile is changed, an adjustment quantity in the coloradjustment profile and the adjustment quantity of the adjusted color 206by the color adjustment may not always coincide with each other.

[0082] Note that the color adjustment profile is not limited to Lab→Lab,and it may be from a device independent color space to a deviceindependent color space.

[0083] Hereinafter, local color adjustment by spot selection as anexample will be described using steps 1303 to 1306 of FIG. 13.

[0084] By the above-described detection method of an adjusted colorusing color difference as an index, referring to mask blank and colordifference of each pixel in the preview image, the user selects anadjusted color using spot selection 802 (an adjusted color selectionunit 1303). From positional information on the spot-selected image, theLab value 203 and the Lab value 206 corresponding to the spot-selectedadjusted color are obtained. Color difference at the pixel positiondesignated using the spot selection 802 (the value obtained by theequation 1.1) is displayed in AE in an information window of FIG. 9. Theuser can select the adjusted color using AE as a quantitative index.

[0085] Next, color adjustment is performed using a color adjustment unit1304. First, adjustment conditions are set based on the adjusted color.In this embodiment, as the adjustment conditions, three parameters ofinfluence range, weighting, and the adjustment quantity to the adjustedcolor, are used.

[0086] The influence range to the adjusted color is adjusted by a sliderbar 803 of degree of influence. FIG. 7A shows CLUT (Lab→Lab) in a coloradjustment profile. In case of spot selection, on a Lab color space, theinfluence range of color adjustment is represented as a sphere whosecenter is at the target color 203 to the selected adjusted color 206 andwhose radius is degree of influence. When the degree of influence isincreased, the adjustment quantity to the adjusted color goes to have aninfluence in a wider range.

[0087] When the user designates the degree of influence by the sliderbar 803 of degree of influence, it is judged whether or not each Labvalue 203 of the sample image is within the influence range (sphere) ofcolor adjustment. In case of inside, mask setting is performed, and itis informed to the user by bask blink or the like on the preview image206 (FIG. 9). Thus, by performing mask blink, the user can visually beinformed of the degree of influence of color adjustment, and can referto it when the degree of influence is set.

[0088] Next, using the screen shown in FIG. 10, the adjustment quantityto the adjusted color is determined. Here, LCh adjustment in which theadjustment quantity is set on an LCh color space, as an example, will bedescribed.

[0089] The user can independently set an adjustment quantity to each ofL (brightness), C (chroma), and h (hue). Upon this, referring to ΔE1003, Δa, and Δb 1004 as hue of adjustment results, the user set theadjustment quantity. ΔL, Δa, and Δb 1004 can be obtained by convertingeach of the Lab value 203 and the Lab value 206 on the LCh color space,and obtaining the difference to each of the L, C, and h components.

[0090] Note that, in this embodiment, although LCh adjustment has beendescribed, also in CMYK adjustment and Lab adjustment, only color spacechanges, and it is processed like LCh.

[0091] In case of Lab adjustment, an adjustment quantity canindependently be set to each of the L, a, and b components. And, byobtaining the difference to each of the L, a, and b components of theLab value 203 and the Lab value 206, ΔL, Δa, and Δb are calculated anddisplayed.

[0092] Thus, in this embodiment, in accordance with the color space ofthe adjustment method indicated by the user, displayed information ischanged. By this, the user is made easy to set the adjustment quantity.

[0093] Although the influence range is represented in the coloradjustment profile by the sphere whose center is the target color 203,only by selection of the adjusted color and designation of the degree ofinfluence, it is not determined how the adjustment quantity is reflectedin the sphere. The influence distribution in the sphere is determined byweighting setting 1002. FIGS. 7A and 7B two-dimensionally show examplesof influence distributions set by the weighting setting 1002. FIGS. 7Aand 7B show a Gaussian distribution (normal distribution) and a lineardistribution, respectively. That is, in the color adjustment profile, tothe target color 20, the adjustment quantity of the user is directlyreflected, and the color around it is adjusted according to theinfluence distribution so that the influence may decrease as thedistance increases. For example, in LCh adjustment 1003, when thebrightness L to the adjusted color 206 is intended to be finely adjustedby about +5, the brightness L to an input of the target color 203 isfinely adjusted by about +5, and in the color on the surrounding grid,the adjustment quantity changes in accordance with the distance from thetarget color. Also, as for chroma C and hue h, the color on the grid isadjusted according to the influence distribution.

[0094] Results of the color adjustment are reflected on the coloradjustment profile 601 of through, and by performing processing of FIG.6B, the color-adjusted preview image 207 can be obtained.

[0095] A color-difference calculation unit 1305 evaluates processingresults of FIG. 6B every time when the user changes the value of coloradjustment. More specifically, the Lab value 203 of the adjusted colorselected by the color selection unit 1303 and the Lab value 206color-adjusted are calculated by the equation (1.1), and they aredisplayed as AE of FIG. 10.

[0096] As the user uses this AE as an index, till the satisfactorypreview image 207 is obtained, color adjustment is repeated (step 1306).

[0097] According to this embodiment, color adjustment is performed sothat color difference may decrease. Although fine color adjustment wasdifficult in color adjustment by eye observation on the monitor, byintroducing the quantitative index by color difference, color adjustmentthat was difficult by eye observation is possible.

[0098] (Color Adjustment History, Save/Insertion of Color AdjustmentAction, and Color-Difference Log)

[0099]FIG. 6C shows a conceptional view of a color adjustment history,and FIG. 11 shows the color adjustment history and a color-differencelog.

[0100] In FIG. 11, reference numeral 1101 denotes cancel of a coloradjustment action, reference numeral 1102 denotes redo of the coloradjustment action, reference numeral 1103 denotes display of acolor-difference evaluation, reference numeral 1104 denotes insertion ofthe color adjustment action, and reference numeral 1105 denotes save ofthe color adjustment action.

[0101] As shown in FIG. 6C, every time when each color adjustment actionperformed by the user is determined (step 1307), it is added as a listof the color adjustment profile (step 1309). In case of canceling thecolor adjustment action last applied (1101), canceling can be executedby eliminating the color adjustment profile 602 last added, from thelist. Also, one or more applied color adjustment actions can becanceled. In case of redoing the color adjustment action once canceled(1102), the color adjustment profile can be again added to the list.

[0102] At the same time, a color-difference statistic is calculatedevery time when each of various kinds of color adjustment actionsperformed by the user is determined (1308). As the color-differencestatistic, average color difference within the color reproduction range,average color difference to the sample image, etc., can be selected.

[0103] As the average color difference within the color reproductionrange, the Lab value equal to the whole color space is input, colorsincluded in the color reproduction range are extracted from colorreproduction information (gamut Tag) of the output profile 105 of theCMYK printer 106, and the average color difference of the original Labvalue 203 and the preview Lab value 206 when processing of FIG. 6A or 6Cis performed, is obtained.

[0104] As the average color difference to the sample image, colorsincluded in the color reproduction range are extracted from the originalimage 203 of the sample image, and likewise the average color differenceof the original Lab value 203 and the preview Lab value 206 is obtained.

[0105] As color-difference statistics, not only the average colordifference but also the minimum color difference, the maximum colordifference, the standard deviation, etc., are calculated at the sametime. As shown in FIG. 11, the statistics obtained here are displayed asthe color difference log together with the color adjustment history(1309).

[0106] By displaying the color difference log, it can be quantitativelyjudged whether or not the color adjustment performed by the user waseffective adjustment. If the average color difference has increased,cancel of the color adjustment action is performed, and better coloradjustment can be tried again.

[0107] Besides, by executing the display button (1103) of the colordifference evaluation, not only the average color difference but alsothe statistics of the maximum color difference, the standard deviation,etc., can be displayed. FIG. 12 is an example of display of a colordifference evaluation.

[0108] Further, by selecting an optional color adjustment action of thecolor adjustment history, and executing the display button of the colordifference evaluation, the statistics at the time of the selected coloradjustment action can be displayed as shown in FIG. 12.

[0109] In case that the same color adjustment is intended to be used foranother profile, or an color adjustment action is intended to be reused,the color adjustment profile list can be saved on an external storagedevice (1105 of FIG. 11, and 1311 of FIG. 13), or insertion to thepresent color adjustment profile list from the external storage device(1104 of FIG. 11, and 1302 of FIG. 13) is also possible. Here, in caseof saving the color adjustment profile list consisting of a plurality ofcolor adjustment actions, the user can select whether the coloradjustment profile list (601 to 602) is saved as it is, or the coloradjustment profile list (601 to 602) is saved after it is synthesizedinto one color adjustment profile.

[0110] (Profile Saving after Color Adjustment)

[0111] As shown in FIG. 6D, by synthesizing the color adjustment profilelist (601 to 602) and the output profile 105 [B2A] of the CMYK printer106, and updating the output profile 105 [B2A] by the synthesizedresults, a profile after color adjustment can be obtained.

[0112] As described above, according to this embodiment, by utilizingcolor difference upon color adjustment, a quantitative evaluation notinfluenced by the experience and sensitivity of the user can beperformed. In addition, by calculating the color difference between theoriginal image and the preview image, by detecting an area in which thecolor difference is large in the sample image, and informing the user,it makes it easy for the user to select the adjusted color.

[0113] Since the user is informed of the color adjustment results of theprofile by color difference, the adjustment results can quantitativelybe evaluated. In particular, since the user is informed of various colordifference statistics as evaluation values, the user can evaluate fromvarious viewpoints. In the average color difference, by displaying thecolor difference statistic to the inside of the color reproduction range(excluding the outside of the color reproduction range from thecalculation objects), a more specifically quantitative evaluation can beperformed.

[0114] Further, since the history of adjustment is history-displayedtogether with the evaluation value, a quantitative evaluation can beperformed upon each adjustment, and the user can easily check theadjustment history.

[0115] (Other Embodiments)

[0116] It is also within the scope of the present invention that acomputer in an apparatus or system connected with various devices inorder to operate the various devices to realize functions of theabove-described embodiment is supplied with software program codes forrealizing the functions of the above-described embodiment, and thecomputer (CPU or MPU) of the system or apparatus operates the variousdevices in accordance with the installed program.

[0117] In this case, since the software program codes themselves are torealize the functions of the above-described embodiment, the presentinvention includes the software program codes themselves and means forsupplying the program codes to the computer, for example, a storagemedium storing the program codes.

[0118] As the storage medium storing the program codes usable are, forexample, a floppy disk, a hard disk, an optical disk, a magneto-opticaldisk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, etc.

[0119] Besides, not only in case that the functions of theabove-described embodiment are realized by the computer executing thesupplied program codes, but also in case that the program codescooperate with the OS (Operating System), another application softwareprogram, or the like, operating on the computer, to realize thefunctions of the above-described embodiment, it is needless to say thatthe program codes are also included in embodiments of the presentinvention.

[0120] Further, it is needless to say that the present inventionincludes also a case in which the supplied program codes are stored in amemory provided in a function extension board of the computer or afunction extension unit connected with the computer, then a CPU or thelike provided in the function extension board or unit performs part orthe whole of an actual process based on instructions of the programcodes, and the functions of the above-described embodiment are realizedby the process.

[0121] According to the present invention, upon adjustment of a profile,a quantitative evaluation not influenced by the experience andsensitivity of a user can be made.

[0122] Besides, by making it possible to register adjustment in ahistory, the history of adjustment can be checked.

What is claimed is:
 1. A profile adjustment method for adjusting firstconversion data for converting device independent data included in aprofile describing characteristics of a device into device dependentdata, comprising the steps of inputting sample data which is the deviceindependent data, converting the sample data into the device dependentdata using the first conversion data, converting the converted devicedependent data into the device independent data using second conversiondata which is conversion data included in the profile and which isconversion data for converting the device dependent data into the deviceindependent data, and calculating a color difference between the sampledata and the device independent data.
 2. The profile adjustment methodaccording to claim 1, wherein an adjusted color and an adjustmentquantity are input based on a user instruction, the first conversiondata is adjusted based on the adjusted color and the adjustmentquantity, and the color difference in the adjusted color is displayed.3. The profile adjustment method according to claim 1, wherein a sampleimage shown by sample data as the device independent data is displayedas an original image, and a preview image based on device independentdata converted using the second conversion data is displayed.
 4. Theprofile adjustment method according to claim 3, wherein the colordifference at a position instructed by a user is displayed on theoriginal or preview image.
 5. The profile adjustment method according toclaim 3, wherein a user is informed of a part of the preview image wherethe color difference is not less than a predetermined color difference.6. The profile adjustment method according to claim 5, wherein thepredetermined color difference is set in accordance with an instructionof the user.
 7. The profile adjustment method according to claim 1,wherein an adjusted color and an adjustment quantity are input based ona user instruction, the first conversion data is adjusted based on theadjusted color and the adjustment quantity, the adjustment quantity canbe set using an optional adjustment methods selected out of a pluralityof adjustment methods, and a color difference in accordance with theselected adjustment method is displayed.
 8. A profile adjustment methodcomprising: an adjustment step of adjusting first conversion data forconverting device independent data included in a profile describingcharacteristics of a device into device dependent data, an evaluationstep of evaluating results of the adjustment, and a registration step ofregistering the adjustment in a history, wherein the history isdisplayed, and an evaluation corresponding to the adjustment registeredin the history is displayed.
 9. The profile adjustment method accordingto claim 8, wherein a color difference statistic is obtained in theevaluation step.
 10. The profile adjustment method according to claim 8,wherein a plurality of color difference statistics are displayed toadjustment selected from the displayed history by an indication of auser.
 11. The profile adjustment method according to claim 8, wherein,in the evaluation step, a color difference to data in a colorreproduction range of the device and a color difference statistic isobtained.
 12. The profile adjustment method according to claim 8,wherein the adjustment can be saved and the saved adjustment can be readout to be applied.
 13. A profile adjustment apparatus for adjustingfirst conversion data for converting device independent data included ina profile describing characteristics of a device into device dependentdata, comprising: input means for inputting sample data which is thedevice independent data, means for converting the sample data into thedevice dependent data using the first conversion data, means forconverting the converted device dependent data into the deviceindependent data using second conversion data which is conversion dataincluded in the profile and which is conversion data for converting thedevice dependent data into the device independent data, and means forcalculating a color difference between the sample data and the deviceindependent data.
 14. A program for realizing an adjustment method foradjusting first conversion data for converting device independent dataincluded in a profile describing characteristics of a device into devicedependent data, comprising the steps of inputting sample data which isthe device independent data, converting the sample data into the devicedependent data using the first conversion data, converting the converteddevice dependent data into the device independent data using secondconversion data which is conversion data included in the profile andwhich is conversion data for converting the device dependent data intothe device independent data, and calculating a color difference betweenthe sample data and the device independent data.
 15. A program forrealizing a profile adjustment method comprising: an adjustment step ofadjusting first conversion data for converting device independent dataincluded in a profile describing characteristics of a device into devicedependent data, an evaluation step of evaluating results of theadjustment, and a registration step of registering the adjustment in ahistory, wherein the history is displayed, and an evaluationcorresponding to the adjustment registered in the history is displayed.